Electrical connection structure for magnetic heads and method of making the same
An electrical connection structure suitable for use in a magnetic head and disk drive, as well as a method of making the same, are disclosed. An electrically conductive etch stop layer is formed over a first electrically conductive layer. An electrically conductive diffusion barrier layer is then formed over the electrically conductive etch stop layer, followed by the formation of an insulator layer over the electrically conductive diffusion barrier layer. Next, a patterned photoresist is formed over left and right regions of the insulator layer so as to expose a central region of the insulator layer. Utilizing an etching process with the patterned photoresist in place, insulator materials of the insulator layer in the central region are removed to form a via which exposes electrically conductive materials in the central region. Finally, a second electrically conductive layer is formed within the via over the electrically conductive materials in the central region. Advantageously, the electrically conductive diffusion barrier layer reduces or eliminates oxidation of a top surface of the electrically conducting etch stop layer during the formation of the electrical connection.
1. Field of the Technology
This invention relates generally to electrical connection structures for magnetic recording devices, and more particularly to an electrical connection structure having an electrically conducting diffusion barrier layer which reduces or eliminates oxidation of a top surface of an electrically conductive etch stop layer of the electrical connection structure.
2. Description of the Related Art
Computers often include auxiliary memory storage devices having media on which data can be written and from which data can be read for later use. A direct access storage device (disk drive) incorporating rotating magnetic disks are commonly used for storing data in magnetic form on the disk surfaces. Data is written on concentric, radially spaced tracks on the disk surfaces by a write head, and is then read by a read head. Thin film magnetic heads are primarily used in magnetic storage systems to write/read information in the form of magnetic pulses to/from the disk. A magnetic transducer, such as an inductive or magnetoresistive head (e.g. MR or GMR type), includes a read sensor which detects a magnetic field through the change in the resistance of its sense layer as a function of the strength and direction of the magnetic flux being sensed by the sense layer. The magnetic head is typically formed on a slider which is then mounted to a suspension arm of an actuator. The suspension arm suspends the head in close proximity to a disk surface.
Electrical current flows through the read sensor through low electrical resistance paths known in the art as lead layer structures. These lead layer structures are terminated at the trailing edge of the slider and are connected to an electrical current source through electrical connections known in the art as “vias”. When the electrical connections include a metal that is prone to oxidation, the surface oxide can impede the flow of the electrical current through any via utilized for the electrical connection.
One example is an electrical connection structure which includes copper (Cu) and tantalum (Ta), where the Ta is utilized as an etch stop layer. In this example, a lead/shield layer of nickel-iron (NiFe) needs to make electrical contact with the lead layer structure through the via. During the fabrication process, the top surface of the Ta is exposed to oxygen whereby the surface of the Ta oxidizes, thereby becoming electrically resistant. If the lead/shield layer is subsequently deposited in contact with this oxidized surface then a parasitic resistance results.
One known solution utilizes in-situ sputter cleaning or in-situ ion milling prior to the deposition of the lead/shield layer. Disadvantages of this approach include an increased likelihood of damage to other structures in the magnetic head. Specifically, in the above example, a read gap layer is damaged and/or thinned by the sputter cleaning or ion-milling. This damage reduces the desired characteristics of mechanical stability, chemical stability, and low contact resistivity.
Accordingly, what are needed are improved electrical connection structures for magnetic recording devices and methods of making the same.
SUMMARYAn electrical connection structure suitable for use in a magnetic head and disk drive, as well as a method of making the same are described herein. An electrically conductive etch stop layer is formed over a first electrically conductive layer. An electrically conductive diffusion barrier layer is then formed over the electrically conductive etch stop layer, followed by the formation of an insulator layer over the electrically conductive diffusion barrier layer. Next, a patterned photoresist is formed over left and right regions of the insulator layer so as to expose a central region of the insulator layer. Utilizing an etching process with the patterned photoresist in place, insulator materials of the insulator layer in the central region are removed to form a via which exposes electrically conductive materials in the central region. Finally, a second electrically conductive layer is formed within the via over the electrically conductive materials in the central region. Advantageously, the electrically conductive diffusion barrier layer reduces or eliminates oxidation of a top surface of the electrically conducting etch stop layer during the formation of the electrical connection.
BRIEF DESCRIPTION OF THE DRAWINGSFor a fuller understanding of the nature and advantages of the present invention, as well as the preferred mode of use, reference should be made to the following detailed description read in conjunction with the accompanying drawings:
An electrical connection structure suitable for use in a magnetic head and disk drive, as well as a method of making the same are described herein. An electrically conductive etch stop layer is formed over a first electrically conductive layer. An electrically conductive diffusion barrier layer is then formed over the electrically conductive etch stop layer, followed by the formation of an insulator layer over the electrically conductive diffusion barrier layer. Next, a patterned photoresist is formed over left and right regions of the insulator layer so as to expose a central region of the insulator layer. Utilizing an etching process with the patterned photoresist in place, insulator materials of the insulator layer in the central region are removed to form a via which exposes electrically conductive materials in the central region. Finally, a second electrically conductive layer is formed within the via over the electrically conductive materials in the central region. Advantageously, the electrically conductive diffusion barrier layer reduces or eliminates oxidation of a top surface of the electrically conducting etch stop layer during the formation of the electrical connection.
The following description is the best embodiment presently contemplated for carrying out the present invention. This description is made for the purpose of illustrating the general principles of the present invention and is not meant to limit the inventive concepts claimed herein. %
Referring now to the drawings wherein like reference numerals designate like or similar parts throughout the several views,
Write head portion 70 of magnetic head 40 includes a coil layer 84 sandwiched between first and second insulation layers 86 and 88. A third insulation layer 90 may be employed for planarizing the head to eliminate ripples in the second insulation layer caused by coil layer 84. The first, second and third insulation layers are referred to in the art as an “insulation stack”. Coil layer 84 and first, second and third insulation layers 86, 88 and 90 are sandwiched between first and second pole piece layers 92 and 94. First and second pole piece layers 92 and 94 are magnetically coupled at a back gap 96 and have first and second pole tips 98 and 100 which are separated by a write gap layer 102 at the ABS. Since second shield layer 82 and first pole piece layer 92 are a common layer, this head is known as a merged head. In a piggyback head an insulation layer is located between a second shield layer and a first pole piece layer. As shown in
Referring to
Alternatively, as shown in
Utilizing an etching process with the patterned photoresist in place, insulator materials of the insulator layer in the central region are removed to form a via which exposes electrically conductive materials in the central region (step 1114 of
As described previously, electrical current flows through a read sensor through low electrical resistance paths known in the art as lead layer structures. These lead layer structures are terminated at the trailing edge of the slider and are connected to an electrical current source through electrical connections known in the art as “vias”. When the electrical connections include a metal that is prone to oxidation, the surface oxide can impede the flow of the electrical current through any via utilized for the electrical connection. One example is an electrical connection structure which includes Cu and Ta, where the Ta is utilized as an etch stop layer. In this example, a lead/shield layer of NiFe needs to make electrical contact with the lead layer structure through the via. During the fabrication process, the top surface of the Ta is exposed to oxygen whereby the surface of the Ta oxidizes, thereby becoming electrically resistant. If the lead/shield layer is subsequently deposited in contact with this oxidized surface then a parasitic resistance results. One known solution known in the art utilizes in-situ sputter cleaning or in-situ ion milling prior to the deposition of the lead/shield layer. Disadvantages of this approach include an increased likelihood of damage to other structures in the magnetic head. Specifically, in the above example, a read gap layer is damaged and/or thinned by the sputter cleaning or ion-milling. This damage reduces the desired characteristics of mechanical stability, chemical stability, and complete electrical isolation. Using techniques in the present application, an electrically conducting diffusion barrier layer reduces or eliminates oxidation of a top surface of an electrically conductive etch stop layer of the electrical connection structure.
Beginning with
In
Next, in
In general, electrically conductive etch stop layer 1084 is a layer of material that is resistant to etching process 1790 of
During a conventional fabrication process, the Cu/Ta structure is brought into air whereby the surface of the Ta oxidizes to become electrically resistant. Any subsequently deposited electrically conducting layer formed in contact with this oxidized surface results in a parasitic resistance in the electrical connection. This provides an ineffective electrical connection.
In
Next, in
Next in
Next in
Referring now to
As discussed previously, electrical connection structures 980 and 990 of
Final Comments. An electrical connection structure suitable for use in a magnetic head and disk drive, as well as a method of making the same, have been described. An electrically conductive etch stop layer is formed over a first electrically conductive layer. An electrically conductive diffusion barrier layer is then formed over the electrically conductive etch stop layer, followed by the formation of an insulator layer over the electrically conductive diffusion barrier layer. Next, a patterned photoresist is formed over left and right regions of the insulator layer so as to expose a central region of the insulator layer. Utilizing an etching process with the patterned photoresist in place, insulator materials of the insulator layer in the central region are removed to form a via which exposes electrically conductive materials in the central region. Finally, a second electrically conductive layer is formed within the via over the electrically conductive materials in the central region. Advantageously, the electrically conductive diffusion barrier layer reduces or eliminates oxidation of a top surface of the electrically conducting etch stop layer during the formation of the electrical connection.
It is to be understood that the above is merely a description of preferred embodiments of the invention and that various changes, alterations, and variations may be made without departing from the true spirit and scope of the invention as set for in the appended claims. For example, the conductive studs described herein may be utilized in any other suitable device, such as a semiconductor device. None of the terms or phrases in the specification and claims has been given any special particular meaning different from the plain language meaning to those skilled in the art, and therefore the specification is not to be used to define terms in an unduly narrow sense.
Claims
1. An electrical connection structure, comprising:
- a first electrically conductive layer;
- an electrically conductive etch stop layer formed over the first electrically conductive layer;
- an electrically conductive diffusion barrier layer formed over the electrically conductive etch stop layer; and
- a second electrically conductive layer formed over the electrically conductive diffusion barrier layer.
2. The electrical connection structure of claim 1, wherein the electrically conductive etch stop layer comprises tantalum (Ta).
3. The electrical connection structure of claim 1, wherein the electrically conductive diffusion barrier layer comprises ruthenium (Ru).
4. The electrical connection structure of claim 1, wherein one of the first and the second electrically conductive layers is coupled to one of a read head and a write head.
5. The electrical connection structure of claim 1, wherein the electrically conductive diffusion barrier layer reduces or eliminates oxidation of a top surface of the electrically conductive etch stop layer.
6. The electrical connection structure of claim 1, further comprising:
- left and right insulator material portions formed over the electrically conductive diffusion barrier layer; and
- wherein at least a portion of the second electrically conductive layer is formed between the left and the right insulator material portions.
7. The electrical connection structure of claim 1, further comprising:
- wherein the electrically conductive etch stop layer is formed over and in contact with the first electrically conductive layer;
- wherein the electrically conductive diffusion barrier layer is formed over and in contact with the electrically conductive etch stop layer; and
- wherein the second electrically conductive layer is formed over and in contact with the electrically conductive diffusion barrier layer.
8. The electrical connection structure of claim 1, further comprising:
- wherein the electrically conductive etch stop layer has a first etching property; and
- wherein the electrically conductive diffusion barrier layer has a second etching property different from the first etching property.
9. A magnetic head, comprising:
- at least one of a read head portion and a write head portion;
- an electrical connection structure which electrically connects the at least one read head portion and write head portion to an electrical component;
- the electrical connection structure including: a first electrically conductive layer; an electrically conductive etch stop layer formed over the first electrically conductive layer; an electrically conductive diffusion barrier layer formed over the electrically conductive etch stop layer; and a second electrically conductive layer formed over the electrically conductive diffusion barrier layer.
10. The magnetic head of claim 9, wherein the electrically conductive etch stop layer comprises tantalum (Ta).
11. The magnetic head of claim 9 wherein the electrically conductive diffusion barrier layer comprises ruthenium (Ru).
12. The magnetic head of claim 9, wherein one of the first and the second electrically conductive layers is coupled to a read sensor of the read head portion.
13. The magnetic head of claim 9, wherein the electrically conductive diffusion barrier layer reduces or eliminates oxidation of a top surface of the electrically conductive etch stop layer.
14. The magnetic head of claim 9, further comprising:
- left and right insulator material portions formed over the electrically conductive diffusion barrier layer; and
- wherein at least a portion of the second electrically conductive layer is formed between the left and the right insulator material portions.
15. The magnetic head of claim 9, further comprising:
- wherein the electrically conductive etch stop layer is formed over and in contact with the first electrically conductive layer;
- wherein the electrically conductive diffusion barrier layer is formed over and in contact with the electrically conductive etch stop layer; and
- wherein the second electrically conductive layer is formed over and in contact with the electrically conductive diffusion barrier layer.
16. The magnetic head of claim 9, further comprising:
- wherein the electrically conductive etch stop layer has a first etching property; and
- wherein the electrically conductive diffusion barrier layer has a second etching property different from the first etching property.
17. A disk drive, comprising:
- at least one rotatable magnetic disk;
- a spindle supporting the at least one rotatable magnetic disk;
- a disk drive motor for rotating the at least one rotatable magnetic disk;
- a magnetic head for reading data from the at least one rotatable magnetic disk;
- a slider;
- at least one of a read head portion and a write head portion carried on the slider;
- an electrical connection structure for use in electrically coupling the at least one read head portion and write head portion to an electrical component;
- the electrical connection structure including: a first electrically conductive layer; an electrically conductive etch stop layer formed over the first electrically conductive layer; an electrically conductive diffusion barrier layer formed over the electrically conductive etch stop layer; and a second electrically conductive layer formed over the electrically conductive diffusion barrier layer.
18. The disk drive of claim 17, wherein the electrically conductive etch stop layer comprises tantalum (Ta).
19. The disk drive of claim 17 wherein the electrically conductive diffusion barrier layer comprises ruthenium (Ru).
20. The disk drive of claim 17, wherein one of the first and the second electrically conductive layers is coupled to a read sensor of the read head portion.
21. The disk drive of claim 17, wherein the electrically conductive diffusion barrier layer reduces or eliminates oxidation of a top surface of the electrically conductive etch stop layer.
22. The disk drive of claim 17, further comprising:
- left and right insulator material portions formed over the electrically conductive diffusion barrier layer; and
- wherein at least a portion of the second electrically conductive layer is formed between the left and the right insulator material portions.
23. The disk drive of claim 17, further comprising:
- wherein the electrically conductive etch stop layer is formed over and in contact with the first electrically conductive layer;
- wherein the electrically conductive diffusion barrier layer is formed over and in contact with the electrically conductive etch stop layer; and
- wherein the second electrically conductive layer is formed over and in contact with the electrically conductive diffusion barrier layer.
24. The disk drive of claim 17, further comprising:
- wherein the electrically conductive etch stop layer has a first etching property; and
- wherein the electrically conductive diffusion barrier layer has a second etching property different from the first etching property.
25. A method of making an electrical connection, comprising:
- forming a first electrically conductive layer;
- forming an electrically conductive etch stop layer over the first electrically conductive layer;
- forming an electrically conductive diffusion barrier layer over the electrically conductive etch stop layer;
- forming an insulator layer over the electrically conductive diffusion barrier layer;
- forming a patterned photoresist over left and right regions of the insulator layer to thereby expose a central region of the insulator layer;
- etching away, with the patterned photoresist in place, insulator materials of the insulator layer in the central region to thereby expose electrically conductive materials in the central region; and
- forming a second electrically conductive layer over the insulator materials and the electrically conductive materials in the central region.
26. The method of claim 25, wherein the electrically conductive etch stop layer comprises tantalum (Ta).
27. The method of claim 25, wherein the electrically conductive diffusion barrier layer comprises ruthenium (Ru).
28. The method of claim 25, wherein the act of etching comprises a wet etch.
29. The method of claim 25, wherein the electrically conductive diffusion barrier layer reduces oxidation of a top surface of the electrically conductive etch stop layer during the method of making.
30. The method of claim 25, wherein the electrically conductive materials exposed in the central region after the act of etching comprises the electrically conductive diffusion barrier layer.
31. The method of claim 25, wherein the electrically conductive materials exposed in the central region after the act of etching comprises the electrically conductive etch stop layer.
32. The method of claim 25, further comprising:
- wherein the electrically conductive etch stop layer has a first etching property; and
- wherein the electrically conductive diffusion barrier layer has a second etching property different from the first etching property.
Type: Application
Filed: Nov 30, 2004
Publication Date: Jun 1, 2006
Patent Grant number: 7623319
Inventors: Mustafa Pinarbasi (Morgan Hill, CA), Howard Zolla (San Jose, CA)
Application Number: 10/999,265
International Classification: G11B 5/147 (20060101);